Ocular bioavailability of topical prednisolone preparations.

Research on the anti-inflammatory effects of prednisolone sodium phosphate and prednisolone acetate is reviewed critically and methodological problems in the study of ocular drugs are identified. A pharmacokinetic model of the absorption of water-insoluble drugs, such as prednisolone acetate, and water-soluble drugs, such as prednisolone sodium phosphate, is presented. The steps in the model are the drug elimination rate in the precornea and anterior chamber, the rate of drug dissolution, the rate of drug penetration into the cornea, and the rate of drug transport into the aqueous humor. Both prednisolone sodium phosphate and prednisolone acetate have been shown to have moderate to high anti-inflammatory effects, but it is concluded that the drug solution (prednisolone sodium phosphate) has certain advantages over the drug suspension (prednisolone acetate).